libzfs: zfs_crypto_create() requires a new key by definition: set newkey

This changes the password prompt for new encryption roots from
  Enter passphrase:
  Re-enter passphrase:
to
  Enter new passphrase:
  Re-enter new passphrase:
which makes more sense and is more consistent with "new passphrase"
now always meaning "come up with something" and plain "passphrase"
"remember that thing"

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11866

lib/libzfs/libzfs_crypto.c

@@ -954,7 +954,7 @@ zfs_crypto_create(libzfs_handle_t *hdl, char *parent_name, nvlist_t *props,
 		}
 
 		ret = populate_create_encryption_params_nvlists(hdl, NULL,
-		    B_FALSE, keyformat, keylocation, props, &wkeydata,
+		    B_TRUE, keyformat, keylocation, props, &wkeydata,
 		    &wkeylen);
 		if (ret != 0)
 			goto out;